3 ms·

Tough to rule it out I suppose, and would be interesting to know purely as a matter of history, but I really don't see the attraction of it as an idea in of its

Tough to rule it out I suppose, and would be interesting to know purely as a matter of history, but I really don't see the attraction of it as an idea in of itself. The emergence of primitive proto-cells, then unicellular life, whereever it originated, seems quite easy to understand, and I'd agree with Stuart Kaufmann's "At home in the universe" suggestion that it appears more inevitable given a few environmental prerequisites than something requiring an extraordinary explanation. If interstellar RNA(?) did find it's way to earth, then it was likely competing with home-grown primitive cells, given what we know about early earth conditions and the inevitable rise of complexity. The basic idea is that all it took for life/evolution to get started was a circular chain of chemical reactions (a primitive/proto-metabolism - consuming environment chemicals, and producing others) and some type of semi-permeable container (eventually to become a cell wall) such as a fatty bubble made out of hydrocarbons that can be produced in early-earth conditions. That's all evolution would have needed to get started - some froth on the seashore (or by the deep sea vent/whereever) "competing" with other flavors of froth for numerical supremacy. The more interesting phases of evolution, which it seems are less inevitable (or perhaps I should say lower probability - but nonetheless inevitable given enough time) are things like the emergence of multi-cellular life, or what triggered the "Cambrian explosion" of variety to emerge.

matt-attack 4y ago
Is the formation of DNA from the proto cells you’re describing, not still a pretty big mystery?
- HarHarVeryFunny 4y ago
  Well, that obviously would have been something that evolved too, from simple beginnings. The progression must have from proto-cells that formed and replicated due to general environmental factors (prevailing chemicals/polymers, wave/thermal agitation, etc), to ones that eventually did so progressively more due to their individual chemistry, to varying degrees of success. Any aspect of the chemistry of a particular "colony" of proto-cells that played a role in helping create/preserve the chemical contents and structure of these proto-cells could be regarded as the earliest precursors of RNA/DNA. For example, if the localized chemistry generated self-serving catalysts, or transformed environmental chemicals into others that helped stabilize or produce the proto-cell bubble/container, then these become the beginnings of a colony that is self-defining and beginning to differentiate itself - starting to encode it's own structure. For sure there's a long ways from these types of humble beginning to full blown RNA/DNA, but plenty of scope for the types of incremental improvement that would have driven evolution (better ability to utilize environmental chemicals and energy sources, better ability to survive environmental changes, better ability to replicate and disperse, etc, etc.).

matt-attack 4y ago

Is the formation of DNA from the proto cells you’re describing, not still a pretty big mystery?

HarHarVeryFunny 4y ago
Well, that obviously would have been something that evolved too, from simple beginnings. The progression must have from proto-cells that formed and replicated due to general environmental factors (prevailing chemicals/polymers, wave/thermal agitation, etc), to ones that eventually did so progressively more due to their individual chemistry, to varying degrees of success. Any aspect of the chemistry of a particular "colony" of proto-cells that played a role in helping create/preserve the chemical contents and structure of these proto-cells could be regarded as the earliest precursors of RNA/DNA. For example, if the localized chemistry generated self-serving catalysts, or transformed environmental chemicals into others that helped stabilize or produce the proto-cell bubble/container, then these become the beginnings of a colony that is self-defining and beginning to differentiate itself - starting to encode it's own structure. For sure there's a long ways from these types of humble beginning to full blown RNA/DNA, but plenty of scope for the types of incremental improvement that would have driven evolution (better ability to utilize environmental chemicals and energy sources, better ability to survive environmental changes, better ability to replicate and disperse, etc, etc.).